Asian Scientist Magazine (Sep. 9, 2022) — Greenspaces—such as parks and public gardens—in urban areas provide many benefits including a space to exercise to helping lower ambient temperatures. In fact, the United Nations has specified as part of its 11th Sustainable Development Goal that ‘universal access to greenspaces in urban settlements’ must be provided.
However, accurately measuring whether a country is succeeding in its attempt to provide equitable access to greenspaces has been a challenge for researchers. Some methods include greenspace per capita, where the gross green area is divided by the total population. But such methods don’t account for population density, a nation’s access to adequate resources for planning and creating greenspaces as well as various socioeconomic factors that affect a person’s ability to access such spaces.
In a recent paper published on Nature Communications, researchers from Hong Kong and the United States developed a new methodology to accurately measure greenspace accessibility, with a focus on discovering inequality in greenspace planning and provisions between countries in the Global North and the Global South.
High-resolution vegetation mapping satellite data for the year 2020 was obtained for 1,028 cities across the Global North and Global South, alongside a high-resolution population dataset from that same year. The vegetation mapping data—corresponding with greenspaces present in urban areas such as large cities, smaller towns, and counties—was then weighted against the population dataset. This determined whether areas with a higher population density had greater access to greenspaces, or vice versa. The team also looked at various factors that could affect a person’s ability to access said greenspaces, including geographical accessibility and socioeconomic factors. This then provided the ‘greenspace coverage’, or the supply and demand of greenspaces in a city adjusted to its ease of accessibility.
Overall, results showed that urban settlements in the Global South had greater inequitable access to greenspaces, despite having a significantly higher population density compared to the Global North. In fact, greenspace inequality in the Global South is almost twice that in the Global North. Looking deeper into the data, researchers found the driver behind this disparity in greenspace access is due to greenspace provision and urban landscape design.
What does that mean? Singapore, for example, has a high greenspace coverage of 84%. However, only 55% is actually accessible to the population, either due to the geographical location of the greenspaces, lack of transport, or the fact that some of these greenspaces require people to pay in order to access them.
Bin Chen, lead author and one of the lead investigators in this study, concluded that this study has provided further insight into the inequitable access of greenspace provision and exposure in the Global South. In the paper, Chen called for “greening policies that mitigate environmental disparity in order to achieve [the] sustainable development goals”.
This means that policymakers, city planners and urban landscapers in the Global South should take into consideration a person’s ability to access transportation, money and the overall location and provision of these greenspaces to ensure everyone can access and benefit from them.